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Biomedical subjects

G Liu

Publications and source records attributed to G Liu.

At least 145 records · Page 8Linked to original sources
PubMed2001

Regulation of L-selectin expression by a dominant negative Ikaros protein.

Ikaros family members play critical roles in hematopoietic development, yet molecules regulated by Ikaros proteins remain incompletely characterized. To determine the requirements for functional Ikaros proteins, we overexpressed Ik7, a dominant negative Ikaros protein, in human cell lines and hematopoietic progenitor cells. Ik7 is known to block the normal function of other Ikaros family members in human and mouse cells. Retroviral-mediated overexpression of Ik7 affected two distinct, migratory properties of the CEM T-cell line. Ik7 down-regulated L-selectin cell-surface expression, an effect not a result of increased shedding but of a decrease in L-selectin mRNA levels. Ik7 also reduced the spontaneous migration of CEM T cells in 3-D collagen gels. A reduction in L-selectin, cell-surface expression was also induced by Ik7 in CD34+ hematopoietic progenitor cells. In contrast, the Reh B cell line showed an up-regulation of L-selectin, cell-surface levels when expressing Ik7. For the first time, this study defines an effect of Ikaros proteins in the control of migration-related properties and shows that intact Ikaros proteins are important in a cell type-specific manner for the normal regulation of L-selectin expression.

Animals↗
PubMed2001

[Study of noninvasive intracranial pressure monitoring by bioelectric impedance method].

The changes of intracranial components and corresponding brain impedance were analyzed while intracranial pressure was increasing, and the relation of intracranial pressure pulse wave and brain impedance pulse wave were discussed. A theory of noninvasive intracranial pressure monitoring by bioelectric impedance was put forward. The result of primary experiment suggested that the theory be feasible.

Animals↗
PubMed2001

[Expression of human anti-HBsAg-interferon fusion protein in CHO cells].

OBJECTIVE: To study the possibility of expressing human anti-HBsAg-interferon fusion protein in CHO cells as a putative targeting drug for hepatitis B. METHODS: Both the heavy and light chain genes of human anti-HBsAg antibody derived from a phage display library were fused with alpha-2b interferon (IFN-alpha-2b) gene in vitro by polymerase chain reaction. The IFN alpha-2b gene was placed at the C terminal and a 15 amino acid linker was introduced at the fusion site. The light chain-IFN expression plasmid pLIC was constructed with a mammalian expression vector pcDNA3.1(+) and the heavy chain-IFN expression plasmid pFID was constructed with another mammalian expression vector pCdhfr1. These plasmids and the anti-HBsAg full-length light and heavy chain expression plasmids (pLIC and pHFD, respectively) were transfected into CHO (dhfr-) cells by the following three combinations:I, pLIC + pHFD;II, pLIC + pFID; III, pLFC + pFID. The cultured supernatant of the transfected cells was collected and assayed for IFN activity and HBsAg affinity. RESULTS: The supernatant of combination I and II displayed IFN activity but only combination I supernatant exhibited HBsAg affinity. CONCLUSIONS: The successful expression of a fusion protein with both HBsAg affinity and interferon activity may lead to a new way to make a targeting drug for hepatitis B.

Animals↗
PubMed2001

The interaction between microsomal epoxide hydrolase polymorphisms and cumulative cigarette smoking in different histological subtypes of lung cancer.

Microsomal epoxide hydrolase (mEH) is involved in the metabolism of environmental and tobacco carcinogens. Smaller studies found inconsistent results in the relationship between mEH polymorphisms and lung cancer risk. We investigated the two polymorphisms of mEH in 974 Caucasian lung cancer patients and 1142 controls using PCR-RFLP techniques. The results were analyzed using generalized additive models and logistic regression, adjusting for relevant covariates. There was no overall relationship between mEH genotypes and lung cancer risk. The adjusted odds ratio (OR) of the very low activity genotype versus that of other genotypes combined was 1.00 [95% confidence interval (CI), 0.74-1.34]. However, gene-environment interaction analyses revealed that the ORs decreased as cumulative smoking (defined as square root of pack-years) increased. When pack-years = 0, the OR was 1.89 (95% CI, 1.08-3.28). When pack-years = 28.5, the OR was 1.00 (95% CI, 0.76-1.32), and when pack-years = 80, the OR decreased to 0.65 (95% CI, 0.42-1.00). When cases were stratified according to histological subtypes, the interaction between mEH genotype and cumulative smoking was statistically significant (P < 0.01) for the 222 squamous cell carcinoma cases, whereas it was not significant (P = 0.18) for the 432 adenocarcinoma cases. In conclusion, cumulative cigarette smoking plays a pivotal role in the association between mEH polymorphisms and lung cancer risk, altering the direction of risk (in the case of the very low activity genotype) from a risk factor in nonsmokers to a relatively protective factor in heavy smokers.

Adult↗
PubMed2001

[The use of limit amplitude technique in clinical cardiac electrical signal recording].

Based on the electrophysiologic mechanism of cardiac electrical action and the theory of voltage effect, the limit amplitude technique was employed to obtain the best clinical record effects. The results showed that limiter could limit the oversize signals overlapping each other and make the tiny signals magnification without distortion, such as the His bundle deflection in His Bundel Electrogram. At the same time, all signals recorded at multichannel physiologic recorder were clear and did not interfere with each other. Furthermore, the limiter not only improved the recording quality but also protected the cardiac electronic equipment because overdue stimulation signal was limited at a given electronic level during the recording of transesophageal pacing.

Electrocardiography↗
PubMed2001

[Quality of aquatic environment at Haihe River and the pollutant fluxes flowing into sea].

On the basis of the data of water quality monitored from 1993 to 1997, the pollution indexes of each pollutant was computed. The results showed that the pollution at Haihe river was severe. The rank of water quality at all monitoring site were between IV and V grade. The main pollution factors were NH3-N, NO2-N and organic contaminants. During the 5 years, water quality of Haihe River was improved, however, the pollutant fluxes flowing into Bohai Bay, especially CODMn, BOD, NH3-N, NO3-N and NO2-N, were increased, they were increased from 1555, 655, 337, 156 and 25 t.a-1 in 1993 to 8710, 4317, 2516, 1528 and 188 t.a-1 in 1996, and sharply decreased to 1331, 973, 572, 355 and 31 t.a-1 in 1997, respectively. It may be mainly due to the change of runoff at Haihe River.

Fresh Water↗
PubMed2001

[Treatment of severe hepatitis with artificial liver support system and liver transplantation].

OBJECTIVE: To observe and investigate the efficacy of the hybrid artificial liver support system plus liver transplantation in the treatments of patients with severe viral hepatitis. METHODS: Eight severe viral hepatitis patients with metaphase and advanced stage liver failure received the artificial liver support using a self-command extracorporeal hybrid artificial liver support system and orthotopic liver transplantation after the artificial support for 3-14 days. RESULTS: The liver failure of the 8 patients was controlled by the hybrid artificial liver support effectively. All patients were successfully bridged to orthotopic liver transplantation. Four out of the eight patients survived after transplantation. Four patients died of pulmonary infection or hepatorenal syndrome. CONCLUSIONS: Artificial liver support system combined with liver transplantation can be regarded as an efficient measure for the treatment of metaphase and advanced stage patients of severe viral hepatitis.

Adult↗
PubMed2001

[Exercise tolerance in relation to ventilatory drive and respiratory muscle function in COPD].

OBJECTIVE: To assess the relationships between exercise tolerance and respiratory drive and respiratory muscle function in COPD. METHODS: 28 patients with COPD and 26 normal subjects were involved in the study. Routine pulmonary function, pulmonary diffusing capacity, P0.1, PImax were measured at rest. Oxygen consumption (VO2), carbon dioxide production (VCO2), minute ventilation (VE) etc were measured during exercise testing. Borg Scale was recorded simultaneously. Arterial blood gases were measured before and after exercise. RESULTS: (1) PImax in COPD group (40 +/- 15 mm Hg) was significantly lower than that in the normal group [(53 +/- 19) mm Hg, P < 0.05]. P0.1 in COPD group [(2.8 +/- 0.9) mm Hg] was significantly higher than that in the normal group [(2.0 +/- 0.7) mm Hg, P < 0.05]. Inspiratory drive efficacy (VT/P0.1) in COPD group [(0.21 +/- 0.04) L/mm Hg] was significantly lower than that in the normal group [(0.28 +/- 0.07) L/mm Hg, P < 0.05]. P0.1/PImax in COPD group was (0.069 +/- 0.021), significantly higher than that in the normal group [(0.037 +/- 0.009), P < 0.01]. (2) VO2max was correlated with P0.1/Pimax and Borg Scale in COPD patients (r = 0.66, P < 0.01, and r = 0.53, P < 0.05 respectively). Borg Scale was also positively correlated with P0.1/PImax in COPD group (r = 0.49, P < 0.05). CONCLUSION: In addition to airway obstruction and the damaged gas exchange, exercise intolerance in COPD may also be related to the increased respiratory drive and dysfunction of respiratory muscle.

Adult↗
PubMed2001

[An epidemiological study on the factors influencing length of hospitalization for inpatients of burns].

OBJECTIVE: To provide evidence for intervention on secondary prevention of burns through studying the factors influencing the length of hospitalization on inpatients of burns. METHODS: Seven hundred and ninety burnt patients with cluster sampling, combined analyzing with Cox regression and factor analysis. RESULTS: The influential factors on the length of hospitalization in inpatients with burns included a) how did the patients come to the hospital (X3), b) total body surface area involved (X4), c) depth of burns (X5), and d) the time before hospitalization after burnt (X6). The Cox proportional hazard model used was h(t)/h0(t) = e(-0.193 3F1 -0.617 6F2 -0.118 0F3), and the conversion model between factors Fi and original variates were F1 = -0.132X3 - 0.009X4 + 0.655X5 + 0.583X6, F2 = 0.019X3 + 0.875X4 + 0.257X5 - 0.294X6, F3 = 1.010X3 + 0.025X4 - 0.176X5 + 0.030X6. Data showed that the burnt patients had longer hospitalization time when the burns were deep, larger body surface area involved, and with longer delay before getting to the hospitals, where as the patients got cured faster when taken to the hospital by ambulances. CONCLUSION: One of the major prognostic factors of burns was to treat the patients in time. Secondary prevention of burns must be reinforced.

Adolescent↗
PubMed2001

[Water quality of closed polyculture of penaeid shrimp with tilapia and constricted tagelus].

A variety of water quality parameters were monitored in enclosures for the polyculture of penaeid shrimp with tilapia and constricted tagelus. The result showed that the environment of the polyculture systems was better than that of monoculture one. The fluctuation of DO in the water of polyculture enclosures was less violent, and their lowest values were obviously higher than those in monoculture ones. The value of COD and the number of bacteria in the water of polyculture enclosures were significantly lower than those in monoculture ones(t-test, alpha < 0.05), showing that the amount of organic matter in the water of polyculture systems was less than that in monoculture one. The biomass of plankton and the concentration of chlorophyll-a in the polyculture enclosures were also lower, showing that the suppression of the filtering animals to the plankton was obvious. The accumulation of N and P in the sediment of polyculture enclosures was 39.76% and 51.26%, lower than those of monoculture ones, respectively; and the number of bacteria in the sediment was 7.63% lower. Therefore, it is obvious that closed culture system can greatly decrease the effluent to the coastal waters caused by the pond culture industry, and decrease the pollution to the coastal waters.

Animals↗
PubMed2001

[Study on the exercise test in young health men].

OBJECTIVE: To define the reaction of the respiration and circulation; and to find methods to quantitatively evaluation dyspnea and evaluate the methods that determine anaerobic threshold(AT) with the healthy man during exercise. METHODS: Exercise test was used for 43 healthy young man to measure the index of gas metabolism and artery potassium. The relation between the index of Borg scale (BS) and the oxygen uptake per minute (VO2) was observed. The methods of how to obtain anaerobic threshold(AT) were evaluated by the five kinds of gas metabolism. RESULTS: (1) VD/VT were significantly decreased from the rest to the maximal load exercise (0.28 +/- 0.55 vs 0.19 +/- 0.55, P < 0.01). (2) Seran potassium is state of after exercise (3.76 mmol/Lvs +/- 0.29 mmol/Lvs 4.10 mmol/L +/- 0.38 mmol/L, P < 0.01). (3) BS were closely correlated with VO2 during exercise, From the linear regression line 3 variables Borg scale slop(BSS), Threshold load of dyspnea(TLD), and breakpoint load of dyspnea (BLD), could be derived for quantitative evaluation of dyspnea. (4) ATVCO2 were1208 ml/min +/- 233 ml/min, and it were consistent with ATVE and ATVEO2 (P > 0.05). CONCLUSION: The artery potassium is increased after exercise in young health men. The methods of quantrta-tive evaluation of dyspnea can be used during exercise. It is suitable for AT to obtained by the sharp turning point of the carbon dioxide production (VCO2), minute ventilation (VE) and Ventilation equivalent oxygen (VEO2).

Adult↗
PubMed2001

Detailed deletion mapping on chromosome region 9p21 in human periampullary neoplasms.

OBJECTIVE: To further define the extent of chromosome 9p21 deletion in periampullary neoplasms. METHODS: The loss of heterozygosity at 5 microsatellite polymorphic markers on chromosome 9p21 was detected by polymerase chain reaction (PCR), polyacrylamide gel electrophoresis (PAGE) and silver staining in 35 specimens of periampullary neoplasms and their matching blood samples. RESULTS: Fifty percent (4/8) of pancreatic cancer cases showed the loss of heterozygosity at one or more microsatellite loci, with the more frequent sites of D9S974 (37.5%) and D9S942 (28.6%), and some showing consecutive allelic loss. Sixty-two point five percent (5/8) of ampullary carcinoma cases showed loss of heterozygosity at one or more of the loci, frequent site of loss being D9S942 (42.9%) and the next most frequent being IFNA (37.5%) and D9S171 (37.5%). Loss of one locus was observed in 14.2% (1/7) of insulinoma. CONCLUSION: The minimal common region of chromosome deletion in periampullary neoplasms is defined between the D9S974 and D9S942 loci within a 15 kb interval in 9p21, suggesting the involvement of a novel tumor suppressor gene in their carcinogenesis.

Adolescent↗
PubMed2001

[Realization of a new segmental bioelectrical impedance method for assessing body composition: correlation analysis of human body parameters].

The method of segmental bioelectrical impedance analysis for assessing body composition requires measurement of segmental lengths and cross-sectional areas; thus its complexity is increased. This paper reports the correlation analysis of human body parameters and the linear regressions for predicting segmental parameters by use of gender, height and weight. Accordingly, segmental impedance analysis is simplified.

Adolescent↗
PubMed2001

[The value of medical thorascopy].

OBJECTIVE: To study the practicality and feasibility for a physician to diagnose and treat pleural diseases through thoracoscopy. METHODS: To perform open thoracoscopy on 345 patients with a fibrobronchoscope or a hard thoracoscope under local anesthesia and evaluate the safety and tolerance of patients during the operation. RESULTS: (1) Determination of etiology: in 92.7% (227/245 cases) of pleural effusion cases, 75.0% (69/92) of pneumothorax cases, etiologic causes have been determined and 8 cases of pleural tumors were diagnosed. (2) Therapeutic effectiveness: the response rate of malignant pleural effusions was 78.4% (80/102 cases), the cure rate of pneumothorax was 81.5% (75/92 cases) and for empyema, the cure rate was 92.9% (26/28 cases). (3) SAFETY: during operation the ECG, SaO(2), BP, R, P of 98 patients did not show important changes. In 345 patients, 4.3% (15/345) complained a fransceis cheot stiffin. 7% (24/345) showed sinus tachycardia. CONCLUSIONS: (1) Through thoracoscopy, we can observe the whole pleural cavity and can take biopsy specimen under direct observation. It is a good method to get the etiological diagnosis in cause-underdetermined pleural diseases. (2) It is effective and practical to treat difficult pleural effusion, the obstinate pneumothorax, or one that is not suitable for thoracic surgery. (3) It is safe and simple to apply the thoracoscopy under local anesthesia.

Adolescent↗
PubMed2001

Relationship between hyperventilation and intracranial pressure in patients with severe head injury.

With high fatality rate and disability rate, the pathophysiologic changes of severe head injury are complicated. But the method of lowering intracranial pressure (ICP) through artificial hyperventilation is called in question recently. To understand the related changes of the partial pressure of carbon dioxide in artery (PaCO(2)) and the ICP at the acute period of severe head injury, a total of 64 patients with severe head injury were monitored and analyzed on the 3rd day after injury.

Adolescent↗